iMac's 5K Retina Display: Why It Matters (And Why It Doesn't)

The new Apple iMac with 5K Retina display comes with a 5,120-by-2,880-resolution display. That's double the vertical and horizontal lines of the regular 27-inch iMac (2,560 by 1,440) and 27-inch Apple Thunderbolt Display, which were both insanely detailed in their own right.

Though the line count doubled, the individual pixel count jumped from about 3.7 million pixels up to 14.7 million pixels, an almost 300 percent increase. But what does it all mean?

For one thing, all of the fonts look clearer because they've got double the pixels, but they are still scaled to be readable on the display. It's easiest to notice when you have the older 27-inch iMac and new 27-inch iMac with Retina display side by side. Both systems will have the text and windows in iTunes, iPhoto, and Safari at the same physical size on the screen. However, while the text is about the same size, the individual letters and the pictures within iPhoto on the Retina iMac will show in higher resolution, with greater visible detail in the pictures, and smoother letters in the text.

Why Does It Matter?
In the example highlighted at Thursday's Apple event, video editors will be able to view a 4K (Ultra HD) video (3,840 by 2,160) at 100 percent while still having a boatload of pixels left over surrounding the video for media libraries, toolbars, and video timelines, which is certainly a boon for the future Robert Rodriguez in your family. Photo editors will also benefit from the 5K screen, since they won't have to zoom in too far to get the full 1:1 pixel accuracy in their photos.

But it's not only the photo and video guys who will benefit. Since the screen is sharper with infinitely scalable fonts, folks working on Web design will get more out of their layout sheets, since they will be able to zoom in and out over a wider range of resolutions (websites displayed at 1,366-by-768 resolution may have a different impact to users than those displayed at 1,920 by 1,080). Also, spreadsheet ninjas will be able to view many more cells on screen at once (depending on your eyesight).

Why Does It Not Matter?
If you're a general user writing reports and surfing the Web, the 5K Retina display will be nice, but not really worth the upgrade. Sure, you can now view 1080p HD video natively embedded in websites, but is that really worth an extra $300-500? I don't think so.

As confirmed by Apple, the iMac with 5K Retina display doesn't support one of the iMac's best hidden features: Thunderbolt display mode. Buy a "lesser" iMac, and you'll be able to plug a current or newer MacBook, Mac mini, or Mac Pro into the iMac via Thunderbolt and use the display longer than the shelf life of the internal components. At least for now, you can't do that with the new iMac, so you're stuck with a 5K display with aging internals in a half-dozen years or so. Businesses will likely have paid down their capital depreciation by then, but home users don't have that luxury, and hand me downs can only be appealing for so long. A reusable 5K display would hold on to its value for many years longer.

The appeal of a 5K screen seems strong for applications like medical imaging; 3D MRI and even 2D X-Ray display for doctors diagnosing patients, for example. However, Windows has the lion's share of hospital and medical computers, and cross platform issues are not to be take lightly when a glitch could result in serious complications for a patient. If the scaling is off on an image, a consulting doctor could recommend a lesser treatment (radiation instead of surgery, for example) than would otherwise be advised, and the patient could be affected adversely. In a small one-person clinic (with a lot of machines that go ping!), maybe Doctor Smith can buy an iMac, but not for a hospital where medical records and scans have to be shared with a dozen other healthcare organizations.

If you're a gamer, then the Retina iMac is even less appealing. Sure, you can play 3D games at 1,366-by-768 or 1,920-by-1,080 resolution blown up on the iMac's screen, but that's almost like viewing it through a magnifying filter. While still considered high-end, a single AMD Radeon R9 M29XX GPU isn't enough to fill the 5K screen with 3D graphics on ultra settings. You'll need a triple GPU gaming rig like the Falcon Northwest Mach V (GTX 980) to get smooth gameplay on a 2,560-by-1,600 (quad WXGA) display, which is a lot fewer pixels than the 5K Retina.

This shouldn't be surprising, since photo and video users have been Apple's strongest repeat customers for Macs since the 1980s, but even more so than the Apple MacBook Pros with Retina display, the iMac with 5K Retina display is the graphics artists' dream machine. Everyone else is paying for something nice, but it's ultimately overkill.

For more, check out the video below and Old vs. New 27-Inch iMac: Do You Need a 5K Retina Display?